Update at 8:58 p.m.: The temblor started about 8.4 miles below the surface, according to the U.S. Geological Survey. Residents in the Lennox area said china fell off shelves, but there were no reports of more serious damage. The Los Angeles Fire Department is on "emergency quake mode" as a precaution.

It's unclear what fault the quake struck on. The Newport-Inglewood fault, which has produced several powerful temblors, runs through that general area.

Updated at 9:10 p.m.: An initial assessment by the Los Angeles Fire Department found "no major structural damage, no serious injuries," according to spokesman Brian Humphrey's Twitter feed.

Updated at 9:20 p.m.: At the Los Angeles County Sheriff's Lennox station, deputies said the shaking was brief but intense. "It was pretty strong but over in about 10 seconds," said Lt. Kent Wegener. "There are no [immediate] reports of damage. At this point, we are checking all the critical facilities and getting our ducks in a row."

Los Angeles County Fire officials also said they had not received damage reports in residential or industrial areas, including the coastal refineries.

Update at 9:35 p.m.:KCAL interviewed moviegoers at a shopping mall in Redondo Beach who said the quake shook the screen and caused some ceiling tiles to fall. But firefighters said there was no serious damage or injuries. KCAL also reported numerous burglar alarms going off and some people cutting themselves on glass.

Updated at 9:50 p.m.: In Hawthorne, firefighters were called to Chadron Avenue, near Crenshaw Boulevard, where a light pole was damaged during the earthquake. One man also suffered a heart attack, but it was unclear whether that was connected. “Luckily, nothing major so far,” said Hawthorne Police Lt. Michael Ishii.

The earthquake was “a bit deep,” said U.S. Geological Survey seismologist Susan Hough – originating 8.4 miles below the surface. “That tends to make it less sharp – less of a jerky, abrupt motion,” Hough said. As a result, most of the region felt the quake largely as a rolling motion, though some closer to the center felt more of a jolt.

Lucy Jones, seismologist at the U.S. Geological Survey, said the earthquake appears to be consistent with a rupture on the Newport-Inglewood fault. (She said the quake was too small to break the surface, so they can't definitively identify faults.) Jones said this fault isn't typically thought to be capable of producing a major quake like the San Andreas fault. But it was responsible for the 1933 Long Beach earthquake, which measured about 6.3 in magnitude. The Long Beach quake was about as big as seismologists expect from this fault, she said.

"There have been numerous magnitude 3s on it over the years, a cluster of them in the 1980s," she said. "In general, it's an active area."

The quake was initially logged as a magnitude 5 by automatic sensors, but as more data came in, seismologists downgraded it to a magnitude 4.7. It also had an aftershock with a magnitude 3.1 about six minutes later. So far, Jones said, 12,000 people have reported feeling the shaking, including some people in San Diego. She was not surprised at the number of people reporting because the quake shook a pretty densely populated area.

Nothing about the quake or its aftershocks looked unusual, she said. "It’s a real garden variety California earthquake so far."

What’s notable about it is location with respect to people.

She said the most similar earthquake to this one was a temblor that shook the Inglewood area in 1920, and that one was classified as a "minor damaging shock."

--Shelby Grad, Scott Gold, Jia-Rui Chong and Andrew Blankstein

Photo: Employees of a Starbucks at Hawthorne and Artesia Boulevards clean up broken glass that shattered on the floor and
reportedly injured one person who was taken to a nearby hospital. (Jay Clendenin / Los Angeles Times)